From time to time, health conditions emerge that are relative “orphans” when it comes to having the resources of a health care discipline or subspecialty to take ownership or accept responsibility for developing the body of knowledge that underlies their systematic evaluation and treatment. Female sexual dysfunction (FSD) is such a class of conditions. In large measure, this is because until recently female sexual functioning itself was very imperfectly understood and frequently was defined simply as the absence of sexual dysfunction.1 In addition, confusion arises because FSD can possess elements that fall within the purview of multiple health care disciplines: endocrinology, gynecology, psychiatry, psychology, and urology at times all address various aspects of FSD.

Some argue that these conditions are not medical disorders but rather variations in the continuum of normal sexual behavior. With these circumstances as a backdrop, it is small wonder that most health professionals perceive female sexuality and its accompanying spectrum of dysfunctions as enduring mysteries and report little confidence in their ability to diagnose or treat these conditions.

Theories of female sexual functionAlthough there have been earlier significant contributors, it is important to recognize Kinsey’s early observation concerning the enormous variation that exists in women’s responses to sexual stimulation.2 Although not recognized as a pivotal finding at the time, this observation has since become a core realization in our appreciation of female sexual functioning.

A leap of several decades brings us to the work of Masters and Johnson,3 who developed a linear 4-stage conceptual model of female (and male) sexual functioning. Masters and Johnson’s paradigm involved several stages of sexual excitement followed by orgasm and ultimately resolution. Interestingly, Masters and Johnson’s model held no place for sexual desire. The formal integration of sexual desire into the official model that described female sexual functioning had to await the work of Helen Singer Kaplan4 and Harold Lief5 (both psychiatrists). The resulting 3-stage model made its way into DSM-III in 1980.6

In contrast to the linear, sequential models of Masters and Johnson and DSM, Rosemary Basson7 has more recently put forward a competing model of female sexual functioning that is cyclic and intimacy-based. There is no prescribed sequential arrangement among the elements of desire, arousal, etc, in this schema. Basson argues that in many, if not most instances, women begin a sexual encounter from a sexually neutral position rather than having spontaneous sexual desire; they experience elements such as the need for emotional intimacy, sexual arousal, and sexual desire in a cyclic accumulating fashion. Basson contends that wom­en’s principal motivation for sex is more often the need for intimacy or emotional closeness than sexual satisfaction.

Currently, there are adherents to both theories, whom I suspect tend to focus on those aspects of female sexual functioning that their theory best explains. At present, the situation is akin to the field of physics with its 2 theories of light (quantum and wave); each explains certain phenomena very well, and their disjunctive features are ignored.

EpidemiologyIn the most frequently quoted report on the prevalence of FSD in the general population, 43% of women and 31% of men reported having sexual “complaints.”8 This report arose from a large stratified survey focused primarily on HIV, which, although it was well constructed, resulted in several design limitations—among them an age ceiling of 59 years. More recent prevalence percentages range from the low 20s to mid-30s.9 These figures vary widely depending on whether the DSM-IV criterion of “manifest personal distress” was used. When distress is included as a criterion for diagnosis, reported rates of FSD are considerably lower.9,10 Also, rates drop as a function of duration of FSD.

Risk factors for FSD have been repeatedly demonstrated to be age, health (including mental health), and various health behaviors (eg, smoking).9,10 It is probably safe to conclude that FSD is highly prevalent in our society, and that its prevalence increases significantly with age, the presence of chronic health conditions, and at-risk health behaviors. Hypoactive sexual desire disorder (HSDD) has been consistently shown to be the most prevalent of the FSDs.11

Depression, SSRIs, and FSDThe close association between clinical depression and FSD has been noted for many years; estimated rates among individuals with clinical depression often top 50%.12,13 Depressive disorders are more prevalent in women and clinical depression is one of the principal risk factors for FSD.9 In general, the large majority of cases involve low sexual desire. Orgasmic and arousal disorders are less evident or present as secondary aspects of a primary low-desire problem.